Recently, MPEG video compression standards have been widely applied to every field of technology such as a computer, a broadcasting, home electronics and communications. Accordingly, various kinds of video and audio services and a great variety of digital devices for receiving the services have been developed.
Particularly, a digital television plays an important role in delivering information easily and efficiently in daily life. A user can appreciate various broadcastings of a high-definition image and a high-quality sound at home with no difficulty by receiving digital video/audio data compressed through the use of the MPEG technology.
As a digital television has gotten larger and larger in size, a digital television for use in an advertisement or propaganda has been installed in public places. However, there are limitations on a screen size of the digital television, so it's not sufficient to use the digital television as an outdoor video display device.
Conventionally, there has been proposed a multivision forming a large screen by using a plurality of digital televisions.
The multivision system includes a plurality of video display devices and a controller for distributing image signals to the plurality of video display devices and controlling the plurality of video display devices.
The controller may be connected with the plurality of video display devices through a RS-232C cable. If the controller sends a control command to each of the plurality of video display devices in order to adjust a brightness, a contrast, a phase, a horizontal position, a vertical position and a color temperature thereof, the video display device receiving the control command adjusts a brightness, a contrast, a phase, a horizontal position, a vertical position and a color temperature thereof according to the control command.
Conventionally, although screens of the plurality of video display devices can be adjusted through the use of the controller as mentioned above, it is impossible to adjust the screens by using a remote controller.
In detail, since a general remote controller transmits control data consisting of custom data for identifying a manufacturer and user data generated according to a user's input, a user cannot adjust each screen of the plurality of video display devices located adjacently by using the remote controller.
Accordingly, a user experienced in using the remote controller has a difficulty in adjusting the screens of the plurality of video display devices by using the controller as mentioned above.
Further, when the controller is located away from the plurality of video display devices, the user cannot adjust the screen of each video display device while watching a display state of the video display device directly.
Therefore, it is strongly required to develop a technology capable of controlling each video display device of a multivision by using a remote controller while watching a display state of the video display device directly.